1. Field of the Invention
The present invention relates to a recording system to which a plurality of option devices can be connected to a recording apparatus, a recording apparatus, and an option device.
2. Description of Related Art
A recording system having a recording apparatus and a plurality of option devices connected in series to the recording apparatus is known. In the recording system, a control unit (for example, a CPU) is provided to the recording apparatus and each of the plurality of option devices. The control unit of each of the plurality of option devices is connected only to a control unit of another option device which is adjacent in series connection or a control unit of an adjacent recording apparatus so that communication can be performed. Therefore, communication between the control unit of the recording apparatus and the control unit of the option device in any of the second or subsequent stages in the series connection is performed via the control unit of another option device disposed therebetween.
In such a recording system, there is a known technique that a control unit of a recording apparatus transmits data synchronously with the rising edge of a clock to a control unit of an option device in the first stage and grasps the number of option devices connected to the recording apparatus on the basis of the number of clocks until the data returns to the control unit of the recording apparatus via the control units in the option devices in the second and subsequent stages.